Conventionally, a power conversion apparatus (inverter) has been widely used for the purpose of driving a motor for running a vehicle, which is mounted in a vehicle such as an electric vehicle (EV) or a hybrid electric vehicle (HEV) and converts DC power into AC power. Such a power conversion apparatus generally includes a semiconductor element called a power semiconductor element as a switching element, and converts the DC power into the AC power using the power semiconductor element.
In the power conversion apparatus described above, there is a concern about that the power semiconductor element may be broken when an overcurrent flows due to a short circuit. Therefore, PTL 1 discloses a power conversion apparatus as a technique of preventing the power semiconductor element from being broken due to the overcurrent. The power conversion apparatus is provided with a transistor having as emitter sensing terminal as the switching element, and detects a magnitude of a sense current outputting from the emitter sensing terminal according to a current flowing to the transistor to detect the overcurrent.